Jarring tools



Nov. 6, 1962 M. M. KINLEY ETAL 3,062,304

JARRING TOOLS Filed Dec. 23, 1959 4 Sheets-Sheet l Myra/7 M '/(//2/ey 4/050 C ff/n/ey INVENTORS //W M RWY/ M a a F Nov. 6, 1962 JARRING TOOLS Filed Dec. 23, 1959 M. M. KINLEY ETAL 4 Sheets-Sheet 2 tires This invention relates to jarring tools, and particularly to jarring tools for use in wells.

This application is a continuation-in-part of United States patent application Serial No. 599,398, filed July 23, 1956, now abandoned.

An object of this invention is to provide a new and improved jarring tool for applying a jarring force to an object in a Well or similar location by utilizing fluid pressure for initiating the jarring force.

Another object of this invention is to provide a new and improved jarring tool which is adapted to be lowered into a well on a wire line or other support for connection with a stuck choke or other object in the well, the wire line being releasable from the jarring tool prior to the applying of an upward jarring force to the stuck choke or other object with said jarring tool, whereby fouling or twisting of the wire line as a result of the upward movement of the jarring tool following the jarring of the stuck object is avoided.

A further object of this invention is to provide a new and improved tension jar assembly for controlling the amount of jarring force applied to a stuck object connected therewith.

A still further object of this invention is to provide a new and improved jarring tool having a tension jar assembly and a fluid seal therewith for creating upper and lower fluid chambers with a differential in fluid pressure acting on said tension jar assembly to impart a jarring force to a stuck object when a predetermined fluid pressure differential is developed.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and wherein:

FIG. 1 is a view, partly in elevation and partly in section, illustrating the jarring tool of this invention as it is being lowered or run into a pipe for attachment to a stuck object or fish in the pipe;

FIG. 2 is a view similar to FIG. 1, but illustrating the jarring tool of this invention in the jarring position after same has been connected to the stuck object or fish in the pipe but prior to the application of a jarring force to such object or fish;

FIGS. 3A, 3B and 3C are sectional views which together illustrate the details of the jarring tool of this invention in the same jarring position illustrated in FIG. 2;

FIG. 4 is a horizontal sectional view, taken on line 44 of FIG. 3A;

FIG. 5 is a sectional view of a portion of the jarring tool of this invention showing same with the jarring surfaces or shoulders in jarring contact with each other such as would occur when the jarring force is applied with the jarring tool to the stuck object or fish in the P P FIG. 6 is a sectional view of a modified latching assembly for the tension or jarring member;

FIG. 7 is a View, partly in section and partly in elevation, illustrating a modified portion of the tool of this invention; and

FIG. 8 is a cross-sectional view taken on line e s of FIG. 7.

In the drawings, the letter T designates generally the Efifildfil Patented Nov. 6, 1952 jarring tool of this invention which is adapted to be lowered into a well pipe W or other pipe in which a stuck object or fish such as a choke is located (not shown). The jarring tool T is lowered into the pipe W to connect a conventional fishing tool F (a portion of which is illustrated) to the stuck fish. The jarring tool T is preferably lowered on a wire line or other flexible support 10 which is releasably connected to the jarring tool T with a conventional releasable coupling assembly A or any other means for connecting the Wire line 10 to the jarring tool T for lowering the jarring tool T into the well bore and for thereafter permitting the removal of such wire line 10 from the jarring tool T. Conventional sinker bars or weights 12 are also preferably provided at the upper end of the jarring tool T for assisting in the lowering of the jarring tool T into the well pipe W. Briefly, then, the jarring tool T is lowered into the well pipe W 011 the wire line or other flexible support 10, the conventional fishing tool F is connected to the stuck fish, the wire line 10 is manipulated to move the jarring tool T to the position shown in PEG. 2, and the wire line connector A is released from the jarring tool T to permit the removal of the wire line 10 from the pipe W. Also, as will be explained, the fluid pressure in the well pipe W above the jarring tool T is then reduced so that the fluid pressure in the pipe W below the jarring tool T acts thereon to impart a lifting force to the tool T. Such lifting force is changed into a jarring force, as will be explained, which is transmitted to the stuck object below the fishing tool F. Thus, with the jarring tool T of this invention, the fluid pressure in the pipe W is utilized for imparting a jarring force to the stuck fish to free or loosen same for the removal from the pipe W.

Considering the invention in detail, the jarring tool T of this invention includes a tubular body 15 which extends for substantially the full length of the jarring tool T. For purposes of assembly, the body 15 is preferably formed with two upper semi-cylindrical tubular sections 15a and 15b (FIG. 4) which are assembled together with dowel pins 16. The lower ends of the upper semi-cylindrical tubular sections 15a and 1512 are threaded as indicated at for threaded engagement with the threads 15d of the lower tubular body section 15e. The lower ends of the semi-cylindrical body sections 15a and 15b together form a lateral shoulder or jarring surface 15] for receiving the jarring impact or blow, as will be explained.

A fluid pressure sealing member or annular sealing cup 18 which is formed of rubber or other resilient material is mounted on the external surface of the body 15 with a solid clamping ring 19. The sealing cup 18 is adapted to engage the inner surface or bore of the pipe W when the jarring tool is in use for the jarring operation, as will be explained. As can be seen in FIG. 3A, the cup 18 has its open end facing downwardly so that the fluid pressure below the cup 18 is prevented from flowing upwardly around the exterior of the body 15 of the tool T, whereby the space above the cup 18 is an upper chamber in the pipe W and the space below the cup 18 is a lower chamber therein so that when different fluid pressures exist in such chambers there is a differential fluid pressure or force acting across the cup 18.

A plurality of latch fingers 20 extend downwardly from the resilient cup 18 and are positioned within a latch sleeve 22 during the lowering of the jarring tool T into the pipe W so as to hold the outer or external surface of the seal cup 18 out of engagement with the inside surface of the pipe W to prevent the application of a fluid pressure force to the jarring tool during lowering into the pipe. The latch sleeve 22 has inwardly extending tabs or projections 22a which extend into longitudinal slots or openings 15g in the lower tubular body section 15s. When the latch sleeve 22 is holding the latch fingers 20 in the retracted position (MG. 1) to thereby hold the sealing cup 15 in the retracted or inactive position, the latch sleeve 22 is at the upper end of the lower tubular body section 15a and is in frictional engagement with the external surface thereof in the vicinity of the annular nut 25 (PKG. 3B). The inwardly extending tabs or projections 22a are, therefore, near the upper ends of the longitudinal slots 15g, but subsequently, the latch sleeve 22 is lowered, as will be more fully explained hereinafter, so as to move the sleeve 22 downwardly to the position shown in FIG. 3B, whereby the inherent resiliency of the sealing cup 18 causes same to move outwardly to contact the inner surface of the well pipe W (FlG. 3A).

A longitudinally extending jarring member or bar 26 is positioned within the bore of the body 15 for longitudinal movement relative thereto. The bar 26 is threaded at 26:: for connection with the sinker bars 12, or for direct connection to the fishing neck 27 (FIGS. 1 and 2) in the event the sinker bars 12 are not utilized. An annular flange or shoulder 26b is provided near the upper end of the tension bar 26 for engagement with the upper ends of the upper body sections 15a and 15b (FlG. 3A) to limit the downward or inward movement of the bar 26 relative to the body 15.

The bar 26 has an enlarged diameter section 26c which is of substantially the same diameter as the internal diameter of the enlarged diameter bore portion 15/1 of the upper body sections 15a and 15b so that a seal ring 23 formed of rubber or other resilient material is adapted to seal with the enlarged diameter section 26c when the shoulder 26b is in contact with the upper ends of the body sections 15a and 15!). By reason of the enlarged inner bore portion 1511 of the upper body sections 15a and 15b, an annular space is provided between the external surface of the bar 26 below the enlarged portion 260 and the internal bore surface 15h. Fluid communication between the arca in the well pipe W below the resilient cup 18 and the area thcreabove is established through one or more openings film formed near the lower end of the enlarged inner diameter bore portion 15/1 and which communicate with said annular space around the bar 26. Thus, when the bar 26 is raised relative to the body 15 so that the enlarged diameter section 266 of the member 26 is out of the bore portion 1511, which is the case when the jarring tool T is being lowered into the well pipe W (FIG. 1), then fluid communication from the area in the pipe W below the cup 18 t the area above the cup is established through flow into the port or ports m and through the annular space between the bar 26 and the body 15 to the area above the body 15. Thus, the fluid pressure above and below the seal cup 18 is equalized during the running in of the jarring tool T in the well pipe W. However, when the bar 26 has been lowered relative to the body 15 to move the enlarged section 26c into sealing engagement with the seal ring 28, the fluid communication through the ports 15m and the annular area externally of the bar 26 is closed off. Since the seal cup i8 is released to its active position in engagement with the pipe W prior to such closing off of the fluid communication, it is believed evident that the fluid pressure below the seal cup 13 is then directed upwardly against such cup 18, and if the pressure below the cup exceeds the pressure thereabove, an upward force is exerted on the cup 13. Such fluid pressure also acts on the bar 26 tending to urge same upwardly relative to the body 15.

Near the lower end of the bar 26, an annular lateral shoulder or jarring surface 26d (FIG. 3B) is provided. Such jarring surface 26d is normally spaced below the jarring surface 15 but, as will be explained, when a predetermined fluid force is exerted upwardly on the bar 26, the bar 26 is caused to move upwardly relative to the body 15 to bring the jarring surfaces 26d and 15] into jarring contact with each other to impart a jarring 4 force to the body 15 which in turn imparts a jarring force to the stuck object in the well pipe W.

During the lowering or running in of the jarring tool T in the well pipe W, the bar 26 is in a raised position relative to the body 15 (FIG. 1) and is held in such position by a shear pin 30 (FIG. 3B) which extends from the tension bar 26 through the body 15. Such shear pin 36 is severed or sheared by the manipulation of the wire line 10, after the jarring tool T has been lowered in the pipe W and the fishing tool F has been connected to the stuck object, so that thereafter the bar 26 is lowered relative to the body 15 to the position shown in FIGS. 3A and 33.

During such lowering of the bar 26, the latching sleeve 2 is carried downwardly to release the fingers 20. Such downward movement of the latching sleeve 22 is effected with a guide pin 32 which has parallel flat surfaces 32a engageable with the Walls of one of the longitudinal slots 15g. Such guide pin 32 prevents the turning of the bar 26 relative to the body 15 during longitudinal movement of the bar 26 relative to the body 15. A special opening 15p is provided in the body 15 for the assembly of the guide pin 32 at the lower end of the bar 26. Thus, prior to the time that the upper body sections 15a and 15b are threaded into the threads 15d of the lower body section 152, the opening 26e for the pin 32 is aligned laterally with the opening 15p, so that the guide pin 32 is inserted into such opening 260. Thereafter the bar 26 is raised to move the pin 32 into one of the longitudinal slots 15g with the flat parallel guide surfaces 32a in contact with or substantially in contact with, the walls of such slots 15g. The body sections 15a and 1512 are then assembled and threaded into the threads 15d, so that thereafter the pin 32 does not drop downwardly into the opening 15p (FIG. 3B).

For releasably connecting the bar 26 to the body 15 to thereby hold the bar 26 to the body 15 until a predetermined fluid pressure diiferential has been developed across the bar 26, a tension arm 35 is pivotally connected to the body 15 near its lower end. Such tension arm 35 extends into a longitudinal slot 15r and is integrally connected with a resilient adjusting arm 36 (FIG. 30) so that together the arms 35 and 36 form a substantially U-shaped member which is pivotally mounted in the body section 152 by a pivot pin 37 extending therethrough and into the Walls of the body 15c. An adjusting and retaining screw 38 is threaded into the adjusting arm 36 so as to utilize the resiliency of the arm 36 for pulling or pivotally moving the tension arm 35 into contact with a stop pin 39 (FIG. 3B) which is mounted in the walls of the body section 152. Thus, as the adjusting arm 36 is moved to the right (FIGS. 3B and 3C), the tension arm 35 is also moved to the right about the pivot pin 37, but upon the engagement of the tension arm 35 with the stop pin 39, then further movement of the arm 35 to the right is prevented and a further movement of the arm 36 to the right tends to place the arm 35 under an increased tension or force which must be overcome in order to move the arm 35 to the left, or laterally away from the stop pin 39. The amount of such resilient force thus applied to the tension arm 35 by the resilient adjusting arm 36 depends upon the extent to which the arm 36 is pulled to the right by the screw 38 when the arm 35 is in contact with the stop pin 39. In the preferred construction, the adjusting pin 38 has an annular shoulder 38a which contacts the arm 36, and the inner annular surface 38b of the head of the screw 38 engages the bottom surface of a recess 15s, or as shown in the drawings (FIG. 3C), such surface 38b engages a shim or washer 40 disposed at the bottom of the recess 15s. The amount of tension placed in the bar 35 can therefore be readily adjusted by increasing or decreasing the number of the shims 40 so as to move the arm 36 further to the right or to the left. The amount of tension can be calibrated so that the use of varying numbers or thicknesses of shims produces various known predetermined forces on the arm 35 which are selected so as to require various corresponding fluid pressure diiferentials across said cup 18 and said bar 26 to release the member 42 from the arm 35, as will be more evident hereinafter.

The upper end of the tension arm 35 is formed with an inclined hook or inclined surface 35a which is adapted to engage with an inclined surface or shoulder 42a on a laterally movable end member or section 42 disposed at the lower end of the bar 26 (FIG. 3B). The end member or section 42 is slidable laterally in a slot 43 which is inclined downwardly and to the left as viewed in FIG. 313. However, a stop shoulder or bottom 43a is formed in the opening 43 to limit the movement of the end section or member 42 to the left or in a direction towards the arm 35. A lead spring 44 resiliently engages the laterally movable end member 42 for urging same to the position shown in FIG. 3B wherein it is in contact with the bottom surface 43a of the slot 43. The spring 44 is held in position at the lower end of the bar 26 with a threaded screw 45 which preferably has an enlarged head 45a which extends into one of the longitudinal slots 15g diametrically opposite to the slot 15g in which the guide pin 32 is disposed.

In the use or operation of the jarring tool T of this invention, it is lowered into the pipe W with the parts in the position illustrated in FIG. 1 of the drawings, wherein a wire line or other flexible support is connected to the jarring tool T through a conventional connector A. The connector A is releasably attached to the upper end of the tool T through the fishing neck 27 which is mounted above a number of sinker bars 12. Also, a conventional jarring tool (not shown) may be positioned between the fishing neck 27 and the upper end of the jarring tool T to produce a jar suflicient to shear the pin 39 after the jarring tool T has been lowered in the well pipe W. Thus, the tool T is lowered in the pipe W to move the fishing tool F into contact with the stuck choke or other object in the pipe W. The fishing tool F is also of conventional construction and is of the type which engages and becomes connected to the stuck object by simple manipulation of the wire line 10. Such fishing tools F are well known. Thereafter, by the manipulation of the Wire line N, or by a jarring action with the conventional jar previously mentioned (not shown), the shear pin 30 is severed or sheared to permit the tension bar 26 to move downwardly in the body to the position shown in FIG. 2 and in FIGS. 3A-3C. It should be noted that prior to the time that the pin 30 is sheared, the resilient fingers are confined within the bore or interior of the latching sleeve 22 (FIG. 1) to hold the resilient sealing cup 13 in an inactive position out of engagement with the wall of the well pipe W. Also, during the lowering of the jarring tool T in the pipe W, the by-pass for fluid, including gas, is open through the ports 15m and the annular space between the tubular bar 26 and the enlarged diameter bore section 15h and outwardly through the open upper end of body sections 15a and 15b.

However, after the pin 30 has been sheared, the bar 26 moves downwardly by its weight and the weight of the sinker bars 12 and other equipment thereabove. The latching sleeve 22 is carried downwardly with the bar 26 by reason of the engagement of the pin 32 with the tab 22:: therebelow. Finally, the enlarged diameter section 26c of the bar 26 moves into sealing contact with the seal ring 28 when the annular shoulder 26b seats against the ends of the upper body sections 15a and 15b (FIG. 3A). During the movement of the enlarged diameter portion 26c into the bore of the upper body sections 15a and 15b, the laterally movable end section 42 at the lower end of the tension bar 26 is moved downwardly below the hook or lateral surface 35a of the tension arm 35. Such movement is permitted because the inclined surface 42b of the laterally movable member '42 engages with the upper surface of the arm 35 to shift the end section 42 to the right against the action of the spring 44 sufiiciently to let the member 42 pass below the surface 35a to the position shown in FIG. 3B. The spring 44, of course, maintains a. constant pressure on the laterally movable member or section 42 and returns it to the bottom 43a after it has passed below the lateral shoulder 35a on the arm 35. With the arm 35 and the jar 26 thus in position for beginning the jarring action, and with the fishing tool F connected to the stuck object therebelow, the connector A is released from the fishing neck 27 in a known manner to eifect the removal of the wire line or flexible support 10 from the pipe W. Also, at that time the annular fluid pressure sealing cup 18 is in sealing contact with the bore or inner surface of the well pipe W. Thereafter, the pressure in the pipe W is reduced above the seal cup 13 by permitting the pressure in the well pipe W above the jarring tool to bleed off through an open valve at the surface of the well. The pressure of the fluid in the well below the cup 18 is trapped below the cup 18 and a differential in fluid pressure is thereby developed across the cup 18 because of the reduction in the fluid pressure above the cup 18. There is a slight leakage of fluid through the longitudinal spacing between the body sections 15a and 15b (FIG. 4) for a purpose to be hereinafter described. The longitudinal spacing between the body sections 15a and 15b is so slight that it does not interfere with the obtaining of the necessary pressure differential above and below the cup 18 for urging the cup 18 upwardly to obtain the jarring action. When the cup 18 is thus urged upwardly, the body 15 cannot move upwardly because the lower end of the body 15 is directly connected to the stuck fish through the fishing tool F. The aforesaid differential in fluid pressure is created to provide a fluid pressure force acting upwardly upon the bar 26. The bar 26 continues to be urged upwardly by the fluid force until such force acting upwardly thereon reaches a predetermined amount at which time the lateral force on the tension arm 35 which is applied to the right (FIG. 3B) through the resilient arm 36 is overcome to move the arm 35 laterally to the left (FIG. 38) so that the shoulder 42a can pass upwardly above the shoulder 35a. When such movement of the end member 42 above the tension arm 35 occurs, the upward force on the arm 26 causes it to rise very rapidly until the jarring surface 26d contacts the jarring surface 15]. It is to be noted, by Way of example, that a fluid pressure differential in the range of one hundred to three hundred (300) pounds per square inch would normally be suflicient to efiect the release of the member 42 from the tension arm 35 and obtain the jarring action. The slight longitudinal spacing between the body sections 15a and 1512 does not normally interfere with the obtaining of such pressure differentials, and of course such spacing may be made smaller if greater fluid pressure differentials are desired or become necessary under certain well conditions. The jarring impact caused by the contact of the jarring surfaces 26d and 15 is transmitted to the body 15 and thus to the stuck fish connected therebelow so as to apply a jarring force to such stuck fish to loosen or move same. It should be pointed out that even though there is some drop in the fluid pressure difierential acting on the bar 26 when the enlarged portion 260 thereof moves above the seal 28, such drop is not suflicient and does not occur rapidly enough to prevent or substantially reduce the jarring contact between the jarring surfaces 26d and 15 The jarring action may be repeated without removing the tool T from the pipe W by closing the usual well head valves (not shown) at the surface of the well to permit the fluid pressure above and below the cup 18 and the rest of the tool T to equalize. When such equalization occurs, the weight of the bar 26, and the sinker bars 12 if used, cause the bar 26 to fall by gravity relative to the body 15 to re-latch the member 42 below the arm 35 (as in FIG. 3B). During such descent of the bar 2%, the longitudinal space between the body sections 15a and 15b permits enough fluid flow therethrough in addition to the flow '7 through the ports 15m to allow the enlarged section 26c to enter the seal 28 and reach the seated position shown in FIG. 3A. Thereafter, the fluid pressure above the tool T may again be reduced to obtain another jarring stroke. Such jarring strokes can thus be repeated as desired until the fish is loose or it is otherwise desirable to remove the tool T from the well pipe W.

When the fish becomes loosened by such jarring force, the upward force imparted to the jarring tool T by the pressure below the cup 18 continues to act upwardly on same to lift the stuck object upwardly in the well pipe W. The frictional contact of the cup 18 with the pipe W will prevent the tool and connected parts from dropping back down in the pipe W. If the stuck object is merely loosened and is raised upwardly only a small distance in the pipe W, the connector A may be again connected to the fishing neck 27 by lowering same on the wire line so that the jarring tool T can be lifted upwardly on the wire line 10 to remove the stuck object or fish from the pipe W.

In FIG. 6, a modified latching means for releasably holding the jarring member 26 is illustrated wherein a cylindrical rod 142 is utilized instead of the slidable mem ber 42. The guide slot 143 is substantially the same as the guide slot 43, although ordinarily the walls of the slot 143 are at a steeper angle of inclination because the spring 44 is generally eliminated when using the rod 143. The stop surface 143a prevents the rod 142 from rolling out of the slot 143 and such surface 143a corresponds with the stop surface 43a. The operation of the modification of FIG. 6 is substantially the same as with the member 42, but since the spring 44 is usually eliminated when using rod 142, the rod 142 rolls to the stop surface 143a by gravity alone for returning to the latched position below the hook 350:. It is also believed evident that a ball (not shown) could be used instead of the cylindrical rod 142 and such ball would roll in the slot 143 in substantially the same way as the rod 142.

In FIGS. 7 and 8, another modified form of the invention is illustrated. FIG. 7 illustrates the upper portion of the tool T of this invention which corresponds with the upper portion of the tool T shown in FIG. 3A but which is modified as compared to such portion shown therein. The lower portions of the tool T shown in FIGS. 3B and 3C are the same in both forms of the invention except that the body 115 of FIG. 7 is a single tubular member throughout its length rather than being formed in two half sections a and 15b as seen in FIGS. 3A, 3B and 4. FIG. 8 is a view which corresponds with FIG. 4 but further illustrates the construction of the body 115 as a tubular member.

In FIGS. 7 and 8, the bar 126 serves the same purpose as the bar 26 but the upper end thereof has been modified by providing an upper enlarged diameter section 1260 which is slightly smaller in diameter than the bore 11511 of the body 115 so as to provide a restriction to fluid flow between the enlarged diameter section 126C and the bore 11511 during the jarring stroke but also permitting a relatively rapid return of the bar 26 to its re-latched position after a jarring stroke. Thus, it will be appreciated that the circumferential gap or spacing between the section 126 and the bore 115h serves the same purpose as the longitudinal gap or spacing between the body sections 15a and 15b in the form of the invention shown in FIGS. 3A and 4 in particular. In both forms of the invention, such gaps or spacing are exaggerated in the drawings for clarity.

For the purpose of assembly and disassembly, the bar 126 is formed at its upper end with a threaded shank 126g which is threaded into a threaded bore 75a of an adapter 75. Such adapter 75 has an annular lateral shoulder 75b formed thereon to serve as a stop for limiting the downward travel of the bar 26. Such adapter has an upper threaded shank 750 which is threaded into a bore 12a of a sinker bar 12 as shown in FIG. 7, if one or more sinker bars 12 are used.

Except for the above noted differences, the form of the 8 invention shown in FIGS. 7 and 8 is the same as shown in FIGS. 3A and 4, respectively, and the parts that are the same have like numerals and letters in both forms of the invention.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is;

1. A jarring tool adapted to be positioned in .a Well bore, comprising a tubular body having a jarring surface, said body having means therewith for connecting to an object to be jarred, a bar in said body for longitudinal movement relative thereto, said bar having a jarring surface adapted to contact said jarring surface on said lLll'FtH lar body upon a longitudinal movement of said bar rela-' tive to said body, releasable coacting means on said body and said bar for preventing movement of said jarring surfaces towards each other to prevent them from contacting each other until a predetermined fluid pressure differential is developed across said bar so as to exert a predetermined upward force on said bar, an annular seal between said body and the well bore for sealing off the annular space between the well bore and said body as a predetermined pressure differential across said seal is developed, said bar being exposed to the fluid pressure above and below said seal, and co-acting surfaces on said bar and said body for restricting fluid flow through said body until said predetermined pressure differential is developed so that the pressure differential acting on said bar effects the release of said releasable coacting means to obtain a jarring contact between said jarring surfaces.

2. A jarring tool adapted to be connected to an object in a pipe, comprising a first member having a jarring sur face, a second member longitudinally movable relative to said first member and having a jarring surface normally spaced from said jarring surface of said first member but being movable into jarring contact therewith, a seal means between said first member and said pipe adapted to have a pressure differential thereacross, said second member being exposed to the fluid pressure above and below said seal means, a tension means mounted on said first memher, and means on said tension means and on said second member for preventing said second member from being moved longitudinally relative to said first member until a predetermined amount of fluid pressure differential is applied to said second member to release same from said tension means with a movement of said jarring surfaces towards each other and into jarring contact for imparting a jarring force to said object, and means for restricting the flow of the fiuid pressure between said first member and said second member until said predetermined amount of fluid pressure differential is applied to said second member.

3. The structure set forth in claim 2, wherein said tension means includes a tension arm mounted on said first member, and coacting surfaces on said tension arm and said second member engageable with each other prior to applying said predetermined amount of fluid pressure to said second member but being separable from each other when said predetermined amount of fluid pressure is applied to said second member.

4. The structure set forth in claim 2, wherein said seal means includes an annular resilient seal adapted to seal with the pipe and said first member during the applying of the fluid pressure to said second member.

5. The structure set forth in claim 2, wherein said seal means includes an annular resilient seal adapted to seal with the pipe and said first member during the applying of the fluid pressure to said second member, and means for latching said annular resilient seal in an inactive position out of sealing contact with the pipe while running same into the pipe and prior to connection to the stuck object in the pipe.

6. The structure set forth in claim 2, including an adjustment means with said tension means for adjusting the amount of tension developed in said second member and thereby the amount of tension developed in said second member and thereby the amount of said predetermined fluid pressure required before said second member is released from said tension means.

7. A tension assembly for use in imparting a jarring force to an object, including a support member, a tension arm mounted on said support member, a jarring bar longitudinally movable relative to said tension arm, said jarring bar being exposed to a fluid pressure differential tending to urge same longitudinally relative to said tension arm, coacting surfaces on said tension arm and said jarring bar engageable with each other to prevent longitudinal movement thereof away from each other until a predetermined fluid force is applied to said jarring bar, means mounting said tension arm for lateral movement away from the jarring bar, and resilient means urging said tension arm and a portion of said jarring bar laterally towards each other with a predetermined force to maintain said coaeting surfaces in engagement with each other until said predetermined fluid force has been developed at which time said tension arm is laterally moved away from said jarring bar by the coaction of said coasting surfaces to thereby release-said jarring bar from said tension arm for imparting a jarring impact to said object.

8. A tension assembly for use in imparting a jarring force to an object, including a support member, a tension arm mounted on said support member, a jarring bar longitudinally movable relative to said tension arm, said jarring bar being exposed to a fluid pressure differential tending to urge same longitudinally relative to said tension arm, coasting surfaces on said tension .arm and said jarring bar engageable with each other to prevent longitudinal movement thereof away from each other until a predetermined fluid force is applied to said jarring bar, means for restricting the fluid flow around said jarring bar until said predetermined fluid force is developed, means mounting said tension arm for lateral movement away from the jarring bar, and resilient means urging said tension arm and a portion of said jarring bar laterally towards each other with a predetermined force to maintain said coacting surfaces in engagement with each other until said predetermined fluid force has been developed at which time said tension arm is laterally moved away from said jarring bar by the coaction of said coacting surfaces to thereby release said jarring bar from said tension arm for imparting a jarring impact to said object.

9. The structure set forth in claim 8, including means for adjusting the amount of said predetermined force applied by said resilient means to thereby adjust the amount of predetermined fluid force which is required on said jarring bar before same is released from said tension arm.

10. The structure set forth in claim 8, where-in said resilient means is a flexible arm formed integrally with said tension arm, pivot means substantially at the junction between said flexible arm and said tension arm, means connected with said flexible arm to apply a pivoting force to said flexible arm and said tension arm about said pivot means, and a stop means engageable by said tension arm to limit the pivotal movement thereof so that a continued pivoting force applied to said flexible arm and said tension is resisted by the inherent resiliency of the flexible arm which thereby imparts said predetermined force to the jarring bar.

11. The structure set forth in claim 8, wherein said jarring bar has a laterally slidable end section on which the coating shoulder for said jarring bar is formed, said end section being laterally slidable to position its coacting shoulder inwardly of the coacting shoulder on said jarring arm for subsequent coaction in placing said bar under the predetermined tension.

12. The structure set forth in claim 8, including an annular resilient seal adapted to seal with the pipe and said first member during the applying of the fluid pressure to said second member.

13. A jarring tool, comprising a tubular body having a jarring surface thereon, means for connecting said tubular body to an object stuck in a well, sealing means mounted on said body, a longitudinally extending bar positioned in the bore of said tubular body for longitudinal movement relative thereto, said bar having a jarring surface normally longitudinally spaced from said jarring surface on said tubular body but being engageable therewith, tension means mounted on said tubular body but being engageable therewith, tension means mounted on said body and said bar for releasably connecting said bar to Said body for preventing said bar from moving relative to said body until a predetermined fluid force is exerted on said bar to cause it to move longitudinally in said body to bring said jarring surfaces into jarring contact with each other, and coacting surfaces on said bar and said body for restricting fluid flow through said body until said predetermined pressure differential is developed.

14. The structure set forth in claim 13, including a wire line, and means for releasably attaching said wire line to said bar during the lowering of said jarring tool into a Well pipe, said wire line being releasable prior to the ap plying of the fluid pressure differential force to said bar for obtaining the jarring contact of said jarring surfaces.

15. The structure set forth in claim 13, wherein said fluid sealing means is a resilient cup for sealing with apipe in which said tool is positioned, and including a latching sleeve mounted on said body and movable relative thereto, and latching fingers on said resilient cup adapted to be positioned within said latching sleeve for holding said cup in a retracted position out of engagement with said pipe to render said cup inactive by permitting fluid to pass around same, and means on said bar for longitudinally moving said latching sleeve relative to said body and away from said latching fingers to release same whereby the resilient cup engages the pipe for sealing contact therewith.

16. In a tool for moving an object in a well, the combination of a body, engaging means on said body for engaging the object, a pressure seal on said body for sealing the space below said seal from the space above said seal, an anvil on said body, a hammer slidably mounted in said body and adapted to strike said anvil, said hammer being exposed to the fluid pressure above and below said seal so that said hammer is adapted to move longitudinally when a difference in pressure exists above and below said seal, releasable latch means for holding said hammer at a predetermined distance from said anvil until a predetermined difference in pressure above and below said seal has been reached, and means for restricting fluid flow between said body and said hammer until said predetermined difference in pressure has been reached.

17. In a tool for moving an object in a well, the combination of a body having means therewith for connecting to an object, an anvil on said body, a pressure actuated hammer slidably mounted on said body and adapted to strike said anvil, a pressure seal on said body for sealing the space below said seal from the space above said seal, means for restricting fluid flow between said body and said hammer until a predetermined pressure in the well imparts longitudinal movement to said hammer, pressure equalizing means above and below said pressure seal when said hammer has struck said anvil, and latch means preventing longitudinal movement of said hammer relative to said body until the predetermined pressure is developed in the well.

18. In a tool for moving an object in a well, the combination of a body having means therewith for connecting to an object, a pressure actuated jarring member slidably mounted in said body, a pressure seal in sealing engagement with the wall of the well and connected with said body for providing a fluid pressure barrier in the well for sealing off the area on one side of said jarring member from the area on the other side thereof, a latch on said body for releasably engaging said jarring member and releasable by a predetermined fluid pressure differential acting on said jarring member to effect a release and longitudinal movement of said jarring member relative to said body, means on said body and said jarring member adapted to engage with a jarring impact for jarring said object in the well, and means for restricting fluid flow between said body and said jarring member until said predetermined fluid pressure differential is reached.

19. A jarring apparatus, comprising a jarring tool having a pair of jarring members, each of said members having a jarring surface for jarring contact with each other, said jarring tool having latch means for preventing the jarring surfaces on said jarring members from contacting each other until a predetermined tension has been developed in said jarring members, a flexible line for lowering said tool into a well, a releasable attachment means for releasably attaching said flexible line to said jarring tool, connection means on one of said jarring members for connecting same to an object in a well, means externally of said one of said jarring members for restricting fluid pressure flow from the area below said one of said jarring members to the area thereabove to enable a fluid pressure differential to be developed in said well, said attachment being releasable after said connection means is connected to said object, the other of said members being exposed to said fluid pressure differential acting thereacross to apply said predetermined tension to said members to effect a release of the latch means and a jarring contact between said jarring surfaces, and means for restricting fluid flow between said members until said fluid pressure differential is applied to said one of said members.

20. A jarring apparatus, comprising a jarring tool having a pair of jarring members, each of said members having a jarring surface for jarring contact with each other, said jarring tool having latch means for preventing the jarring surfaces on said jarring members from contacting each other until a predetermined tension has been developed in said jarring members, a flexible line for lowering said tool into a Well, a releasable attachment means for releasably attaching said flexible line to said one of said jarring members, connecting means on the other of said jarring members for connecting same to an object in a well, means externally of said one of said jarring members for restricting fluid pressure flow from the area below said one of said jarring members to the area thereabove to enable a fluid pressure differential to be developed in said well, said attachment means being releasable after said connection means on said other of said jarring members is connected to said object, the other of said members being exposed to said fluid pressure differential acting thereacross to apply said predetermined tension to said members to effect a release of the latch means and a jarring contact between said jarring surfaces to thereby apply a jarring force to said object, and means for restricting fluid flow between said members until said fluid pressure differential is applied to said one of said members.

References Cited in the file of this patent UNITED STATES PATENTS 1,848,535 McCullough Mar. 8, 1932 2,345,739 Fisher Apr. 4, 1944 2,733,046 Thompson Jan. 31, 1956 2,805,718 Tausch Sept. 10, 1957 

